Freez Pak Ice Substitute, Reusable, The Tundra

3-3/4 inch x 7-1/2 inch x 1/2 inch. Just freeze and use over and over. Colder than ice. Long lasting. Safe, non-toxic. Leak proof bag. Helpful Hints: Pre-cooled food will stay colder longer with Freez Pak. Stacked Freez Paks keep food cold the longest. A small chest, fully packed, will stay cooler longer than a larger, partially loaded chest.